I took my A7 out to this small patch of mushrooms before I mowed them into oblivion and brought my Nikon 200mm f/2 and my Contax Zeiss 80-200mm f/4 just so see how they compare. The results were fascinating in terms of the technical differences between the two lenses. At f/5.6 and up there's really not any difference between them visually--though I'd expect a chart would say that the Nikon is sharper. Both of these are at f/4. As you can see, the Zeiss has some pretty serious vignetting wide open as well as a nice bit of swirl in the bokeh, whereas the Nikon, being stopped down two stops is nice and smooth with much more even illumination across the frame. Zeiss at f/4 Nikon/Zeiss Comparison by MikeAubrey, on Flickr Nikon at f/4 Nikon/Zeiss Comparison by MikeAubrey, on Flickr I'm not one to buy into the "you buy a fast lens to shoot it wide open" nonsense. Sure, I use them wide open when that's the goal, but a fast lens gives so much else when stopped down compared to other lenses. In this case, f/4 gave me the particular DOF that I was looking for. Is the Zeiss a bad lense? No. For a fairly old 80-200mm zoom at the long end wide open, it is incredibly sharp. It just can't compete with a prime of the Nikon 200mm f2's caliber. And it wasn't supposed to. On the converse, the Zeiss is much better at 80mm, 100mm and 135mm than the Nikon 200mm is. The Zeiss also does a much, much better shop with close ups with its 1m focusing distance vs the Nikon's 2.5m (note that I'm slightly closer in the Zeiss picture than the Nikon, which is at its MFD). If I'm going to hike, I'll be taking the Zeiss. If I'm doing intentional shooting for a project, I'll more likely than not have the Nikon...and a tripod. I think I might continue this thread with more comparison shots over the summer.